Merge pull request #1419 from corona10/string_opt

Micro optimizations for string operations.
pyston · Jan 31, 2017 · 79509a1 · 79509a1
2 parents 88fd8bf + 1f53abd
commit 79509a1
Showing 1 changed file with 29 additions and 0 deletions.
diff --git a/src/runtime/str.cpp b/src/runtime/str.cpp
@@ -1935,6 +1935,14 @@ Box* strRStrip(BoxedString* self, Box* chars) {
 
 Box* strCapitalize(BoxedString* self) {
     assert(PyString_Check(self));
+    int length = self->s().size();
+    if (length == 0)
+        return incref(EmptyString);
+
+    if (length == 1) {
+        char c = std::toupper(self->data()[0]);
+        return incref(characters[c & UCHAR_MAX]);
+    }
 
     std::string s(self->s());
 
@@ -2003,6 +2011,14 @@ Box* strTranslate(BoxedString* self, BoxedString* table, BoxedString* delete_cha
 
 Box* strLower(BoxedString* self) {
     assert(PyString_Check(self));
+    int length = self->s().size();
+    if (length == 0)
+        return incref(EmptyString);
+
+    if (length == 1) {
+        char c = std::tolower(self->data()[0]);
+        return incref(characters[c & UCHAR_MAX]);
+    }
 
     BoxedString* rtn = new (self->size()) BoxedString(self->s());
     for (int i = 0; i < rtn->size(); i++)
@@ -2012,6 +2028,15 @@ Box* strLower(BoxedString* self) {
 
 Box* strUpper(BoxedString* self) {
     assert(PyString_Check(self));
+    int length = self->s().size();
+    if (length == 0)
+        return incref(EmptyString);
+
+    if (length == 1) {
+        char c = std::toupper(self->data()[0]);
+        return incref(characters[c & UCHAR_MAX]);
+    }
+
     BoxedString* rtn = new (self->size()) BoxedString(self->s());
     for (int i = 0; i < rtn->size(); i++)
         rtn->data()[i] = std::toupper(rtn->data()[i]);
@@ -2020,6 +2045,10 @@ Box* strUpper(BoxedString* self) {
 
 Box* strSwapcase(BoxedString* self) {
     assert(PyString_Check(self));
+    int length = self->s().size();
+    if (length == 0)
+        return incref(EmptyString);
+
     BoxedString* rtn = new (self->size()) BoxedString(self->s());
     for (int i = 0; i < rtn->size(); i++) {
         char c = rtn->data()[i];